Tools and Procedures at GRS to Automatically Compare and Modify Fault and Event Trees

Transcription

1 Tools and Procedures at GRS to Automatically Compare and Modify Fault and Event Trees Joachim Herb, GRS /11 Next Generation PSA Software, Methods, and Model Representation Standards Paris, France

2 Motivation PSA have become state-of-the-art since several decades (e.g. in Germany PSA are obligatory since the 1990s) New versions of a PSA are based on already reviewed older versions Therefore it is important to identify the differences between different versions of a PSA Several fault tree analysis cases (e.g. of highly redundant systems) require structurally similar fault trees Modeling of common cause failures Modeling of digital I&C systems Generate fault trees automatically, i.e. let the computer do the work Create a programming language (domain specific language) to model fault trees Most PSA in the world (and all within Germany) use RiskSpectrum Common interface to stored models and data Next Generation PSA Software, Methods, and Model Representation Standards, Paris, France 2

3 Review Approaches for PSA Updates Bottom-up Top-down Start from parameters event trees: Find Compare effects on sequences and Basic consequences events Recursively Fault trees check for changes in Function events Event Fault trees trees sequences and consequences Basic event Parameters Event trees Function events Fault trees Basic events Parameters Next Generation PSA Software, Methods, and Model Representation Standards, Paris, France 3

4 Review Approaches for PSA Updates Bottom-up Start from parameters Find effects on Basic events Fault trees Function events Event trees sequences and consequences Event trees Function events Fault trees Basic events Parameters Next Generation PSA Software, Methods, and Model Representation Standards, Paris, France 4

5 Architecture of GRS Tools to Support the Review of PSA Changes Library of classes representing: Event trees Fault trees (Fault tree pages) Parameters Different tools: Extract data, fault/event tree models from RiskSpectrum Identify differences of fault/event trees Find fault trees which are part of different versions of the PSA Starting from the TOP gate, check for changes of these fault trees: Type of node (AND, OR, K/N, basic event, transfer gate, ) Transfer source (fault tree used as input for transfer gate) ID of node Repeat recursively for all children nodes Output differences-graphs in pdf files Next Generation PSA Software, Methods, and Model Representation Standards, Paris, France 5

6 GRS Tool: Generate Differences-Graphs of Fault Trees Next Generation PSA Software, Methods, and Model Representation Standards, Paris, France 6

7 GRS Tool: Generate Differences-Graphs of Fault Trees Next Generation PSA Software, Methods, and Model Representation Standards, Paris, France 7

8 GRS Tool: Generate Differences-Graphs of Fault Trees Next Generation PSA Software, Methods, and Model Representation Standards, Paris, France 8

9 GRS Tool: Trace Dependencies and Changes of Fault Tree Logic Expand fault trees up- or downwards: Replace recursively all transfer gates through the referenced fault trees Downward expansion: Generate lists of all gates and basic events connected to a specified TOP gate Mark a specified fault tree as recursively equal, if: Fault tree (page) itself has not changed All fault trees (pages) referenced by input transfer gates have not changed For a not recursively equal fault tree output the differing referenced fault trees (pages) Upward expansion: Generate list of all TOP gates affected by changes in a certain fault tree Next Generation PSA Software, Methods, and Model Representation Standards, Paris, France 9

10 Example for Downward Expansion Next Generation PSA Software, Methods, and Model Representation Standards, Paris, France 10

11 Example for Downward Expansion Next Generation PSA Software, Methods, and Model Representation Standards, Paris, France 11

12 Example Applications of the GRS Tools Review of an updated L1 PSA Quality assurance processes during establishment of a Fire PSA Case # of Fault Trees # of Differing Fault Trees # of Event Trees # of Differing Event Trees Review (PSA L1) 2554/ /38 17 Fire PSA 1902/ /75 33 Next Generation PSA Software, Methods, and Model Representation Standards, Paris, France 12

13 Data Link to Modify RiskSpectrum Database using GRS RiskLang Internal data link to RiskSpectrum RiskLang parser generates Ruby objects Open source library ActiveRecord is used to map these objects onto the tables in the RiskSpectrum database Data are added to RiskSpectrum database through ODBC-drivers using SQL commands RiskLang Representation of Fault Trees RiskLang Parser Housekeeping All imported data are tagged in RiskSpectrum User and edit date is set to new value Review/approval information is reset MS Access ODBC Driver Active Record Abstraction Layer MS SQL Server ODBC Driver Export fault trees from RiskSpectrum in RiskLang Generate templates RiskSpectrum PSA Professional RiskSpectrum.NET Next Generation PSA Software, Methods, and Model Representation Standards, Paris, France 13

14 RiskLang Specification to Model Fault Trees Based on the programming language Ruby Add three commands to create fault trees, fault tree nodes, basic events/gates Command Argument Data Type Required Event Types RiskSpectrum Equivalent FT :ID String (max length 21) Yes :circle Basic event :Top FTNode Yes :diamond Diamond basic event :Text String Optional :house House event FTNode :Event Event Yes :orgate OR gate :Transfer Event Yes :andgate AND gate :Pos Integer Optional :kofn K/N gate :InLevel Integer Optional :norgate NOR gate :Children Array of FTNode Optional :nandgate NAND gate Event :ID String (max length 21) Yes :xorgate XOR gate :Type Event Type Yes :comment Comment gate :Text String Optional :continue Continuation gate :Model Integer Optional :notfound - :CalcType Integer Optional Next Generation PSA Software, Methods, and Model Representation Standards, Paris, France 14

15 Exemplary Fault Tree TOP of EX1 TOP1 OR1 AND1 Basic element 1 Basic element 2 Basic element 3 Basic element 4 B1 B2 B3 B4 q=1,00e-03 3 Q=1,00E-03 q=2,00e-03 3 Q=2,00E-03 q=3,00e-03 3 Q=0,00E+00 q=1,00e-03 3 Q=1,00E-03 Next Generation PSA Software, Methods, and Model Representation Standards, Paris, France 15

16 Exemplary Fault Tree require TOP of "RiskRobot/ParseFT" EX1 RiskSpectrumConnection.init('C:\temp\k2.rpp') FT(:ID=>"EX1", :Text=>"Example fault tree", :top=> FTNode(:Event=>Event(:ID=>"TOP1", TOP1 :Type=>:orgate, :CalcType=>1, :Text=>"TOP of EX1"), :Pos=>1, :InLevel=>0, :Children=>[ FTNode(:Event=>Event(:ID=>"OR1", :Type=>:orgate, :CalcType=>1), :Pos=>1, :InLevel=>1, :Children=>[ FTNode(:Event=>Event(:ID=>"B1", :Type=>:circle, :Model=>3, :CalcType=>1, :Text=>"Basic element 1"), :Pos=>1, :InLevel=>1), FTNode(:Event=>Event(:ID=>"B2", :Type=>:circle, :Model=>3, :CalcType=>1, :Text=>"Basic element 2"), :Pos=>2, :InLevel=>1) ]), FTNode(:Event=>Event(:ID=>"AND1", OR1 :Type=>:andgate, AND1 :CalcType=>1), :Pos=>3, :InLevel=>1, :Children=>[ FTNode(:Event=>Event(:ID=>"B3", :Type=>:circle, :Model=>3, :CalcType=>1, :Text=>"Basic element 3"), :Pos=>3, :InLevel=>1), FTNode(:Event=>Event(:ID=>"B4", :Type=>:diamond, :Model=>3, :CalcType=>1, Basic element :Text=>"Basic 1 element 2 4"), :Pos=>4, Basic element :InLevel=>1) 3 Basic element 4 ]) ]) ) B1 B2 B3 B4 q=1,00e-03 3 Q=1,00E-03 q=2,00e-03 3 Q=2,00E-03 q=3,00e-03 3 Q=0,00E+00 q=1,00e-03 3 Q=1,00E-03 Next Generation PSA Software, Methods, and Model Representation Standards, Paris, France 16

17 System Overview of Generic Digital I&C Example L1 T1 F1 L2 T2 F2 L3 T3 F3 L4 T4 F4 AIM1 AIM2 AU1.A AIM1 AIM2 AU2.A AIM1 AIM2 AU3.A AIM1 AIM2 AU4.A AIM ASM AU BP Analogous Input Module Analogous Signal Module Acquisition Unit Backplane CM Communication Module CP Communication Processor PU1.A PU2.A PU3.A PU4.A DIM DOM Digital Input Module Digital Output Module CM3 CM4 LM5 LM6 LM7 LM8 CM3 CM4 LM5 LM6 LM7 LM8 CM3 CM4 LM5 LM6 LM7 LM8 CM3 CM4 LM5 LM6 LM7 LM8 ECCP Emergency Core Cooling Pump F Flow Sensor L Level Sensor VU1.A VU2.A VU3.A VU4.A LM PM PU Link Module Processing Module Processing Unit DOM1.CH1 DOM1.CH2 DOM1.CH1 DOM1.CH2 DOM1.CH1 DOM1.CH2 DOM1.CH1 DOM1.CH2 SV Solenoid Valve SV1-4 ECCP1 SV1-4 ECCP2 SV1-4 ECCP3 SV1-4 ECCP4 T VU Temperature Sensor Voting Unit Next Generation PSA Software, Methods, and Model Representation Standards, Paris, France 17

18 Generic Fault Trees of Digital I&C System Fault Tree ID (wildcards #{r}, #{r2}, #{m}, #{comb}) 2O4_VU#{r}.A_#{comb}_#{m} Description Number of fault trees 372 OR of all combinations leading to a failure of 2 out of for 4 voter AU#{r}.A_#{m}_FNSS Non-self-signaling failure AU 12 AU#{r}.A_FSS Self-signaling failure AU 4 COM_AU#{r}.A_PU#{r2}.A Failure communication AU->PU 16 COM_PU#{r}.A_VU#{r2}.A Failure communication PU->VU 16 ECCP#{r}_#{m} Failure to start ECCP 8 F2M_PU#{r}.A_#{comb}_#{m} All combinations leading to a failure of second min 516 processing unit OUT_AU#{r}.A_#{m}_FNSS Non-self-signaling failure of output AU 12 OUT_AU#{r}.A_#{m}_FSS Self-signaling failure of output AU 12 OUT_PU#{r}.A_#{m}_FNSS Non-self-signaling failure of output PU 12 OUT_PU#{r}.A_#{m}_FSS Self-signaling failure of output PU 12 PU#{r}.A_FNSS Non-self-signaling failure PU 4 PU#{r}.A_FSS Self-signaling failure PU 4 PU#{r}_F2M_#{m}_FNSS Non-self-signaling failure of second min due to input 12 failures from AU in PU SIG_RED#{r}_FSS_#{m} Self-signaling failure of analogous input AU 12 SV#{r}_#{m} Failure to control SV 8 VU#{r}.A_FNSS Non-self-signaling failure VU 4 VU#{r}.A_FSS Self-signaling failure VU 4 VU#{r}_2O4_#{m}_FNSS Non-self-signaling failure of 2 out of 4 due to input failures from PU in VT = 1052 Next Generation PSA Software, Methods, and Model Representation Standards, Paris, France 18 12

19 Conclusions Use cases exists besides the normal application of PSA software (FT, consequence, sequence, importance, MCS analyses): Provide data for documentation Modify existing ET/FT models or create new ones automatically Trace chances Review Lessons learned: One software product can not foresee all user requirements Need an interface (open file format or programming interface) to extend PSA software (i.e. RiskSpectrum ): Import/export PSA models and data (partly implemented by GRS database link/via OpenPSA file format) Trigger computations Access results of analyses Call (external) user defined functions from PSA software Next Generation PSA Software, Methods, and Model Representation Standards, Paris, France 19